摘要:

AbstractThe lithium alkylamide catalyzed addition reaction of α‐methylbenzylamine (1) with styrene was found to produce selectivelyN‐phenethyl‐α‐methylbenzylamine (3). Under the same reaction conditions, addition of (S)‐α‐methylbenzylamine (1′) to 1,4‐divinylbenzene (5) takes place selectively leading to the optically active novel styrene derivative, (S)‐N‐α‐methylbenzyl‐4‐vinylphenethylamine (6), in a one‐step reaction. The specific rotation was found to be [α]4D= −70,1° (c= 1,61 g/dl, in methanol). The followingQ,e‐values and the monomer reactivity rations of6(M1) and styrene (M2) were obtained

ISSN:0025-116X    

DOI:10.1002/macp.1987.021880101

出版商:Hüthig&Wepf Verlag    

年代:1987

数据来源: WILEY

摘要:

AbstractThe mechanism of the reaction of 2,3‐epoxypropyl phenyl ether (2), as a model compound, with 1‐cyanoguanidine (3), for which different pathways have been proposed, is investigated using HPLC and1H NMR spectroscopy. The effect of stoichiometric ratio, temperature and catalytic reagent was studied. It was found that, independent on the stoichiometric ratio, at low temperature, etherification and addition at the primary amino group takes place and reaction of the cyano group only to a low extend. At higher temperature, HPLC diagrams show different peaks indicating a different mechan

ISSN:0025-116X    

DOI:10.1002/macp.1987.021880102

出版商:Hüthig&Wepf Verlag    

年代:1987

数据来源: WILEY

摘要:

AbstractStyrene/1‐hexene copolymers of different chemical composition were prepared with a classical isospecific Ziegler‐Natta catalyst, TiCl3(H)‐AlEt3. Their structure and the distribution of the monomeric unites was analyzed by GPC double detection and1H and13C NMR. The chemical arrangement of isolated and blocked styrene monomeric units between sequences of hexene monomeric units was also investigated.13C chemical shifts of carbon atoms in the copolymers and in addition in model molecules of the two modes of styrene addition indicate that styrene insertion into carbon‐metal bonds of the catalyst proceeds according to a primary mode. Mechanistic implications of these results are di

ISSN:0025-116X    

DOI:10.1002/macp.1987.021880103

出版商:Hüthig&Wepf Verlag    

年代:1987

数据来源: WILEY

摘要:

Abstract2,3‐Epoxypropyl esters were obtained in two steps from carboxylic acids or in one step from their alkali salts by reaction with 1‐chloro‐2,3‐epoxypropane or from the acid chloride with 2,3‐epoxy‐1‐propanol. The kinetic parameters of these reactions were studied with acetic acid and sodium acetate to evaluate the optimal conditions for the synthesis of these esters with the intention to apply them to polymers containing carb

ISSN:0025-116X    

DOI:10.1002/macp.1987.021880104

出版商:Hüthig&Wepf Verlag    

年代:1987

数据来源: WILEY

摘要:

AbstractIt could be shown that the structure of poly(styrylpyridine)s (PSP), which are heat resistant thermosetting resins resulting from the polycondensation of 2,4,6‐trimethylpyridine (1) with terephtalaldehyde (2), is much more complicated than that expected from this polycondensation. 2‐Styrylpyridines were synthesized from benezaldehyde (5) and 2‐methylpyridines and the stability of the respective intermediate alcohol was studied. The thermal behaviour of the styrylpyridines alone or in the presence of their precursors was studied by GPC, IR and NMR spectroscopy and by chemical analyses. It could be shown that the methyl group of 2‐methylpyridine (4) adds reversibly to the double bond of 2‐styrylpyridine (7) to form 2‐phenyl‐1,3‐bis‐(2‐pyridyl)propane (8). This side reaction takes place also in the case of the condensation of1with5. The structures and the reactivity of the condensation products of1with 1,2 or 3 molecules of5(compounds14, 17and18) were studied. The condensation product19, a component of PSP resins, was synthesized from1and2and its reactivity was studied at 200 and 250°C and compared with the non‐methylated derivative 1,4‐bis[2‐(2‐pyridyl)vinyl]benzene (25). The results of a preliminary analysis of the reactions taking place during the PS

ISSN:0025-116X    

DOI:10.1002/macp.1987.021880105

出版商:Hüthig&Wepf Verlag    

年代:1987

数据来源: WILEY

摘要:

AbstractThe structures of the compounds, resulting from the condensation of 2‐methylpyridine, 2,6‐dimethylpyridine and 2,4,6‐trimethylpyridine with benzaldehyde and terephtalaldehyde, were confirmed by high field1H and13C NMR spectroscopy. Structural assignments were made based on the NMR spectra of the intermediate compounds, 4‐[1‐hydroxy‐2‐4,6‐dimethyl‐2‐pyridyl‐ethyl]benzaldehyde (5) and 4‐[1‐hydroxy‐2‐(6‐methyl‐2‐pyridyl)ethyl]benzaldehyde (6), of the main reaction products 2‐styrylpyridine (3) and 1,4‐bis[2‐(4,6‐dimethyl‐2‐pyridyl)vinyl]‐benzene (1), and of the side reaction product 2‐phenyl‐1,3‐bis(2‐pyridyl)propane (4) resulting from the addition of the

ISSN:0025-116X    

DOI:10.1002/macp.1987.021880106

出版商:Hüthig&Wepf Verlag    

年代:1987

数据来源: WILEY

摘要:

AbstractThe polymerization of isobutene with VOCl3in heptane was investigated. In contrast to reports in the literature, the polymerization only starts upon irradiation with light, also when naphthalene is added, and it ceases when the light source is switched off. Thus, it is suggested that the reaction proceeds like a photoinitiated cationic polymerization, and the claim of a living system is not corroborated.

ISSN:0025-116X    

DOI:10.1002/macp.1987.021880107

出版商:Hüthig&Wepf Verlag    

年代:1987

数据来源: WILEY

摘要:

AbstractSilicone films were equilibrated with special organosiloxanes in the presence of hexacholorocyclotriphosphatriene as catalyst in ethers as solvents. Thus, the hydrophobic silicone films developed a hydrophilic surface. This surface treatment does in no way reduce the oxygen permeability of the silicone films. The special organosiloxanes required for the equilibration were produced by addition of allyl compounds containing protected OH‐groups to siloxanes containing SiH‐groups, applying H2PtCl6as catalyst, and subsequent hydrolysis of the addition pro

ISSN:0025-116X    

DOI:10.1002/macp.1987.021880108

出版商:Hüthig&Wepf Verlag    

年代:1987

数据来源: WILEY

摘要:

AbstractSoluble complexes of ω‐lithiumbutenylpoly(styrene‐co‐butadiene) (≈ 100: ≈ 3 DP) with TiCl4were used in conjunction withN,N,N′,N′‐tetramethylethylenediamine (TMEDA), to initiate the polymerization of ethylene. The activity of such a system was measured as a function of the number of amino groups (N) per active center (A. C.) ([N]/[A. C.]). From measurements of the amount of polystyrene‐block‐polyethylene produced and from kinetic studies of the polymerization of ethylene, the influence of TMEDA on both the efficiency of the system and the reactivity of the active species was studied. The depressor effect of the diamine on the reaction parameters, controlling the polymerization of ethylene, was connected with the proposed structure of the active sites. The role of the Lewis base was discussed by assuming a reversible blockage of a vacant coordination site at the titanium throughout the complexation of the electrophilic “host sites” of the polymer [TiCl2,

ISSN:0025-116X    

DOI:10.1002/macp.1987.021880109

出版商:Hüthig&Wepf Verlag    

年代:1987

数据来源: WILEY

摘要:

AbstractDebromination side‐reactions which occur during the synthesis of poly(arylene sulfide)s from copper(I) 4‐bromothiophenoxidesSystematic name: Copper(I) 4‐bromobenzenethiolates.were investigated using bromobenzene as a model for the end unit in a poly(1,4‐phenylene sulfide) chain. Model reactions were conducted in quinoline, pyridine, and 10:1 (v/v) quinoline/pyridine solution in the presence and absence of copper(I) bromide, the condensation product of polymerisation. Reaction liquors were subjected to GLC and MS analysis and evidence is presented which indicates that a copper(I) initiated debromination reaction occurs yielding monophenylquinolines. A mechanism is proposed for the reaction and critically discussed. The consequences of the reaction at the macromolecular level are also de

ISSN:0025-116X    

DOI:10.1002/macp.1987.021880110

出版商:Hüthig&Wepf Verlag    

年代:1987

数据来源: WILEY